Air-conditioning apparatus for



C-, S. CODY April 5, I949.

AIR QONDITIONING APPARATUS FOR COOLING OR HEATING Filed Aug. 1:. 1946 4 Sheets-Sheet 1 OUTSIDE DIR DUCT [6' Eva ralnTon Inm: Am: Dad! INVENTOR Cir/0x05 Em):

ATTORNEY WITNESSES: 5. 34 2L 9; @Y W April 1949. c. s. CODY 2,466,383

AIR CONDITIONING APPARATUS FOR COOLING OR HEATING Filed Aug. 13, 1946 4 Sheets-Sheet 2 '4 q i Ll II E k Q a u 3: 2 s E 5 I4- 5 H \l E kl m E 3 u L] INVENTOR EL/f'f'fi/IO 5Com.

ATTORNEY April 5, C S. CODY AIR COHLHISNIN) APPARATUS FOR COOLING OR HEATING V Filed Aug. 13, 1946 4 Sheets-Sheet 3 E 001. am Era L WITNESSES: INVENTOR (5.1L CurranoEL'aon 9f. @MW- BY ATTORNEY C. S. CODY April 5, 1949.

AIR connmxonma APPARATUS FOR cooum on mmme Filed Aug. 13. 1946 4 Sheets\; set 4 ESQ:

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' INSIDE ORNEY Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE AIR-CONDITIONING APPARATUS FOR COOLING R HEATING Clifford S. Cody, Springfield, Mass, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 13, 1946, Serial No. 690,267 Claims. (Cl. 62129) 1 2 My invention relates to air conditioning ap- Fig. 13 is a fragmentary top plan view of the paratus of the type adapted to be selectively used apparatus shown in Fig. 12. for heating or for cooling the air of a room o In the embodiment illustrated in Fig. 1, the other enclosure. air conditioning apparatus is enclosed in a casing One object of my invention is to produce an 5 I4 which is internally partitioned to form an improved apparatus of the type set forth. evaporator compartment for housing an evapo- A further object of the invention is to produce rator IB, a condenser compartment for housing an improved air conditioning apparatus by means a condenser is and a compressor compartment of which room air, exclusively, may be condifor housing a compressor, not shown. The evaptioned and recirculated, by means of which varil0 orator and condenser are connected in refrigerant able amounts of outside air may be added to the flow relation to each other and to the compressor room air being conditioned and recirculated, by in any well-known manner, not shown, whereby means of which variable amounts of room air compressed refrigerant gas flows from the commay be exhausted to the outside atmosphere, and pressor to the condenser where it is cooled and by means of which room air may be exhausted 15 liquefied, and whereby the liquefied refrigerant from, and outside air may be conditioned and flows from the condenser to the evaporator where introduced into, the room simultaneously. the refrigerant is vaporized, the vaporized re- A still further object of the invention is to frigerant being withdrawn from the evaporator produce an improved apparatus for carrying out by the compressor to complete the cycle. the foregoing objects which will be inexpensive, The casing i4 is provided with a lower air compact and easy to operate. intake chamber 20 and an upper air discharge These and other objects are effected by my chamber 22. The air intake chamber cominvention as will be apparent from the followmunicates with the lower. portions of the evaping description and claims taken in connection orator and condenser compartments and is conwith the accompanying drawings, forming a part nected to the room by a duct 24 and to the outof this application, in which: side atmosphere by a duct 26. The air discharge Fig. 1 is a diagrammatic, perspective view of chamber 22 communicates with the upper por an air conditioning apparatus embodying my intions of the evaporator and condenser compartvention, the apparatus being shown adjusted for ments and is connected to the room by means heating, and certain parts being omitted; of a duct 28 and to the outside atmosphere by Fig. 2 is a reduced, rear elevational view of means ofaduct 30. the apparatus shown in Fig.1; The apparatus further includes a blower 32 Fig. 3 is a reduced diagrammatic top plan view disposed in the evaporator compartment and a of the air conditioning apparatus showing the blower 34 disposed in the condenser compartdamper controlling flow of air from the appara- 35 ment. The blower 32 is adapted to draw air from tus, as adjusted for heating; one side of the air intake chamber 20 through Figs. 4 to 6, inclusive, are reduced diagrama filter 36 and to blow said air into contact with matic views, illustrating some of the positions to the evaporator and into the adjacent side of the which the dampers controlling the admission ,of air discharge chamber 22. This is illustrated air into the apparatus may be adjusted when the 40 by the arrows 38. The blower 34 is adapted to apparatus is used for heating; draw air from the adjacent side of the air in- Fig. '7 is a view similar to Fig. 3, showing the take chamber 20, through a filter l0, and to blow dam per adjusted for cooling; said air over the condenser and into the adjacent Figs. 8 to 10, inclusive, are views similar to side 01 the air discharge chamber 22. This is Figs. 4 to 6. illustrating corresponding positions indicated by the arrows 42. The blowers 32 and of the dampers controlling admission of air into 34 thus discharge separate streams of conditioned the apparatus when the apparatus is usd for air into opposite portions of the air discharge cooling; opening 22. The streams of air delivered into Fig. 11 is a diagrammatic, horizontal sectional the air discharge chamber are separated by means view. illustrating one form of mechanism by of a damper 4B fixedly mounted on the upper means or which the dampers shown in Figs. 4 portion of a shaft 48 and bisecting the air disto 6 and 8 to 10. both inclusive,may be adjusted: charge chamber 22, as clearly shown at the top Fig. 12 is a diagrammatic, front elevational of Fig. i. view of ano her embodiment of the invention When the apparatus is to be used for heating. showing the apparatus adjusted for cooling; and shaft 48 is rotated to move the damper 48 to the that portion of the air position shown in Figs. 1 and 3 in which position air heated by contact with the condenser is discharged into the room through the duct ll while the air used for evaporating the refrigerant in the evaporator is discharged to the outside atmosphere through the duct 30.

When the apparatus is to be used for cooling, the position of the damper 46 is reversed and the air cooled by the evaporator is discharged into the room while the air used for condensing the refrigerant is discharged to the outside atmosphere. Suitable means, not shown, will be provided at a point accessible from the room for moving shaft 48, and hence the damper 46, to either position.

In order to regulate admission of air into the apparatus, the air intake chamber is provided with means Ior selectively connecting the low pressure sides of each of the blowers 52 and 34 with the room, with the outside atmosphere, or

with both, so as to permit either or both of the blowers to draw outside air. or room air, exclusively, or a variable mixture of room air and outside air, and to discharge such air into contact with the evaporator or condenser, respectively.

The means for controlling the admission of air into the intake chamber 20 may be in the nature of a one-piece damper rotatable with the shaft 48 and moved to various positions with reference to the duct 24 leading to the room and the duct 26 leading to the outside atmosphere. As shown, however, the heating chamber 20 is provided with two dampers 50 and 52 which are fastened to the lower adapted to be adjusted to various positions by rotation of the shaft.

Operation When the apparatus is to be used for heating, the shaft 48 is turned so as to bring damper 45 to the position shown in Figs. 1 and 3 in which the upper room duct 28 communicates exclusively with the portion of the discharge chamber 22 which is adjacent the condenser, and the upper outside duct 30 communicates exclusively with discharge chamber 22 which is adjacent the evaporator. In this position of the damper, the air moved by the blower 32 will be discharged to the outside atmosphere through the duct 30, as indicated by the arrow 55, and the air moved by the blower 34 is discharged into the room through the duct 28, as indicated by the arrow 58.

If it is desired to heat and recirculate room air exclusively, the dampers 50 and 52 are adjusted to the position shown in Figs. 1 and 4. In this position of the dampers, the evaporator blower 82 is cut off from the room duct 24 and will, therefore, draw air only through the outside lower duct 25, as indicated by the arrows 6B. As stated, the air drawn by the blower 32 will, after giving up its heat to the evaporator, be discharged to the atmosphere through the duct 30. Conversely, the condenser blower 34 is cut of! from the outside atmosphere so that it can draw room air, exclusively, through the lower duct 24, as indicated by the arrows B2. The air heated by contact with the condenser will be discharged into the room through the upper duct 28.

When it is desired to recirculate and heat the room air while simultaneously introducing some outside air and mixing it with the room air, the dampers 50 and 52 are adjusted to the position shown in Fig. 5, in which the damper 52 is spaced portion of the shaft 48 and from the adjacent wall of the duct 25 so that the condenser blower draws room air, as indicated by the arrows 52, and a certain amount oi outside air, as indicated by the arrows H. In this position, the evapora or blower continues to draw outside air exclusively.

When it is desired to exhaust some of the room air to the outside atmosphere while simultaneously heating some outside air and admitting it into the room, the dampers 50 and 52 are adjusted to the position shown in Fig. 6, in which the evaporator blower draws air irom the outside, as indicated by the arrows B0, and from the room, as indicated by the arrow 56. Likewise, the condenser blower 34 now draws room air, as indicated by the arrows 62, and outside air, as indicated by the arrow 64.

In Figs. 4, 5 and 6, only some of the positions to which the dampers 50 and 52 are adjusted while the apparatus is used for heating, have been shown, but it will be understood that these dampers are capable of being adjusted to other intermediate positions. For example, it the dampers 5|) and 52 are moved to a position at a right angle to the position indicated in Fig. 4, the evaporator blower will draw room air exclusively and discharge it to the outside atmosphere, while the condenser blower will draw outside air exclusively and discharge it into the room. It will also be noted that the upper damper, once adjusted to the heating position as shown in Fig. 1, remains fixed until the apparatus is to be used for cooling and that the air admitted into the apparatus is regulated solely by adjustment of the lower dampers 50 and 52.

When it is desired to un the apparatus for cooling, the shaft 48 is moved so that the damper 46 is adjusted to the position shown in Fig. '7, in which the evaporator compartment and the adjacent portion of the air discharge chamber 22 communicate with the room, as indicated by the arrows 68, and the condenser compartment and the adjacent portion of the air discharge chamber communicate with the outside atmosphere, as indicated by the arrows 10.

When it is desired to cool and recirculate room air, exclusively, the dampers 50 and 52 are adjusted to the position shown in Fig. 8 in which the evaporator blower draws room air, exclusively, as indicated by the arrows 66, while the condenser blower draws outside air, exclusively, in the direction indicated by the arrows 64.

When it is desired to recirculate and cool room air and simultaneously to introduce cooled outside air, while at the same time exhausting some of the room air, the dampers 55 and 52 are adjusted to the position shown in Fig. 9, in which the evaporator blower draws outside air as indicated by the arrows 6B, and inside air as indicated by the arrows 66, while the condenser blower draws room air as indicated by the arrow 62, and outside air as indicated by the arrow 64.

When it is desired to circulate and cool room air only, while at the same time exhausting some of the room air, the dampers 50 and 52 are adjusted as shown in the position of Fig. 10, in which the evaporator blower draws room air exclusively, as indicated by the arrows 66, while the condenser blower draws room air and outside air as indicated by the arrows 62 and 64.

As stated in conjunction with the heating cycle of the apparatus, the dampers 5|) and 52 can be adjusted to other positions, not shown. For example, if the dampers 50 and 52 are adjusted to a position at a right angle to the position shown in Fig. 8, the evaporator blower will draw outside air, exclusively, and the condenser blower will draw room air, exclusively.

In Fig. 11, I show, by way of example, means for connecting the dampers 50 and 52 for movement with shaft 40 and means for limiting the movement of the dampers so as to effect adjustment of the dampers in the manner set forth in connection with Figs. 4 to 6 and 8 to 10. As shown. the dampers 50 and 52 are secured to the lower portion of the shaft 48 by resilient strips I2, and stops I4, I8, I8 and 80 are provided for limiting the movement of the dampers upon rotation of the shaft. The resilient strips I2 are sufiiciently strong to support the weight of the dampers and insure their movement with the shaft, but are sufliciently flexible so as to yield when the movement of either or both of the dampers is restricted by one or more of the stops. The stops may be movably mounted in any deslred manner, as, for example, by means of bolts 82 slidable in slots 84 provided in adjacent walls of the casing.

By this construction illustrated, the stops may be selectively moved into or withdrawn from the lower air intake chamber so as to be disposed in, or withdrawn from, the path of movement of the dampers 50 and 52. In Fig. 11, for example, the stop I4 is shown wholly withdrawn and the stops I6, 18 and 80 are shown as projecting somewhat into the lower air intake chamber. In this position, when the shaft 48 is rotated in clockwise direction, as shown in Fig. 11, the dampers 50 and 52 will rotate with the shaft until the damper 52 abuts the stop I6 and the damper 50 abuts the stop I8. In this position, the evaporator blower will draw a major portion of air from the outside atmosphere as indicated by the arrow 86, and a minor portion of air from the room as indicated by the arrow 08. Simultaneously, the condenser blower will draw a major portion of air from the room as indicated by the arrow 90, and a minor portion from the outside atmosphere as indicated by the arrow 92. Obviously, if the stop I6 is moved further into the air intake chamber 20, the amount of air drawn from the outside atmosphere by the condenser blower will be proportionately increased, and vice versa. When the shaft is rotated in counterclockwise direction as viewed in Fig. 1, the reverse situation will prevail and the position of the dampers 50 and 52 will be controlled by the position of the stops I4 and B0. The shaft 48 may be rotated by any suitable knob or handle, not shown, and the stops may likewise be adjusted by any suitable handle or other means, not shown.

Operation Assuming that it is desired to use the unit for cooling by day and for heating by night, or assuming that the apparatus is to be used for cooling during the warm season and for heating during the cool season, the stops [4, I6, 18 and 80 are adjusted either at the time of the installation of the air conditioning unit or from time to time by the user thereof, so as to regulate the egress and ingress of outside air and room air, respectively, into the lower intake chamber. With the stops so adjusted, it is merely necessary for the user to turn the shaft 48 to move the upper damper 48 from the position shown in Fig. 1 to the position shown in Fig. '7 without the necessity of paying any attention to the dampers 50 and 52. In other words, the rotation of the shaft 48 to move the damper 40 to one or the other of its extreme positions, automatically moves the lower dampers 50 and 52 to predetermined positions so as to regulate the flow of air into or from the room, as desired. For example, as shown in Fig. 11, rotation of the shaft 48 will allow the damper 60 to move through the space between the stops I8 and 00, but will allow the damper 52 to move from the adjacent end of the stop I6 to the other side of the air intake chamber 20.

By this means, the control of the unit by the user is reduced to the simple rotation of the shaft 48 from one extreme position, indicated on an appropriate index (not shown), to another position on said index.

While the structure described is capable of. being operated manually by the user of the apparatus, it is also contemplated to connect the shaft 48 to some conventional form of thermostatically-operated actuating mechanism (not shown) so that, when the temperature of the room falls below a predetermined value, the shaft 48 is automatically turned to the position in which the apparatus is used for heating, and vice versa.

It will thus be seen that whether the shaft 48 is rotated manually or automatically, the upper damper 46 which determines whether the apparatus is to be used for cooling or heating, moves through its full range of movement, while the lower dampers 5B and 52, which regulate the flow of room air and outside air into or from the unit, are moved to positions which are predetermined by the setting of the stops so that the amount of room air or outside air, or a definite mixture of both, which is delivered to the room, can be maintained constant regardless of whether the apparatus is used for heating or for cooling.

In Figs. 12 and 13, there is shown another embodiment of the invention in which the air intake and air discharge passages are placed side by side in the upper portion of the casing, instead of near the bottom and top of the casing, as shown in Fig. 1. By this construction, all ducts will be overhead so as to leave the floor space around the unit unobstructed.

In this embodiment, the casing is provided with an air intake chamber 96 and an air discharge chamber 98. The air intake chamber communicates with the room through a duct I00 and with the outside atmosphere through a duct I02. Likewise, the air discharge chamber 98 communicates with the room through a duct I04 and with the outside atmosphere through a duct I00. The casing is further partitioned to provide a condenser compartment housing a condenser I00, a compressor compartment housing a compressor H0 and an evaporator compartment housing an evaporator II 2. The casing is further provided with a duct or passage II4 leading from the air intake chamber 96 to the lower portion of the evaporator compartment and a duct or passage IIB leading from the condenser compartment to the air discharge chamber 98. In the condenser compartment, there is provided a blower N8, the low pressure side of which communicates with the air intake chamber 96 through the condenser compartment and a filter I20, and the high pressure side of which discharges into the compressor compartment. The blower H8 is thus adapted to draw air from the air intake chamber 06 and to propel the air to the air discharge chamber 98 through the compressor compartment and the passage Hi. In the evaporator compartment is a blower I22 which is adapted to draw air from the air intake chamber 96 through the duct H4 and a filter I24, and to discharge the air over aceasea the evaporator and into the air discharge chamber 98.

The air discharge chamber 93 is provided with a damper I26 mounted on a shaft I28 for rotation into the positions shown by solid and broken lines in Fig. 13. In the solid line position of this damper, the air moved by the blower I22 is delivered into the room in the direction of the arrow I30, while the air moved by the blower I I is discharged to the outside atmosphere in the direction of the arrow I32. In this position of the damper I25, the apparatus is set for cooling the air of the room. Conversely, if the damper I28 is moved to the broken line position shown at the right-hand portion of Fig. 13, the air moved by the evaporator blower I22 through the passage H4 is discharged to the outside atmosphere, as indicated by the arrow I32, while the air moved by the condenser blower I I8 through the duct I I8 will be discharged into the room. as indicated by the arrow I30. In other words, the apparatus is converted from heating to cooling by mere transposition of the damper I26.

The air intake chamber 56 is likewise provided with means for controlling the admission of room air or outside air, or a mixture of both, from either or both of the ducts I00 and I02 into the apparatus. This means may be in the nature of a single damper I34 mounted on a shaft I36 for rotation to the positions shown in solid and broken lines in Fig. 13, or to intermediate positions (not shown). If desired, the damper I34 can be made in two pieces, after the fashion of the dampers 50 and 52.

Operation-Figs. 12 and 13 When the apparatus is to be used for cooling the room air, the damper I25 is adjusted as shown in solid lines in Fig. 13. If it is desired to cool and recirculate room air, exclusively, the damper I34 is adjusted to the position shown in solid lines in Fig. 13, in which position the upper end or the duct III is placed in communication with the room through the duct I00. The evaporator blower I22 now draws room air, exclusively, through the duct H4 and the portion of the air intake chamber 96 adjacent the duct I00. The air moved by the blower I22 is cooled by contact with the evaporator and is discharged into the room through the duct I04 and the adjacent portion of the upper air discharge chamber 90. The

path of flow of the recirculated and cooled room air is indicated by the arrow I40 and I30. Simultaneously, the upper end of the condenser compartment is placed in communication with the outside atmosphere through the duct I02 and the adjacent portion of the air intake chamber 00, so that the blower IIB now draws outside air over the condenser, propels it into the compressor compartment to cool the latter, and discharges the air through the duct I I0, through the portion of the air discharge chamber 98 adjacent the upper end of the duct IIS, and through the outside duct I06. The path of flow of the outside air used for cooling the condenser and the compressor is indicated by the arrows I42 and I32.

When it is desired to cool outside air, exclusively, and admit it to the room, and simultaneously to exhaust room air to the outside atmosphere, the damper I34 is moved to the position shown in broken lines in Fig. 13. In this position, the upper end of the duct H4 is placed in communication with the outside air duct I02 and the upper end of the condenser compartment is placed in communication with the room duct I00. 111' this position, the evaporator blower draws outside air exclusively, while the condenser blower draws room air exclusively.

When it is desired to cool a mixture of outside air and room air and admit it to the room or when it is desired to exhaust room air with or without simultaneously introducing cooled outside air into the room, the damper I34 may be moved to other intermediate positions not speciflcally illustrated.

When it is desired to use the apparatus for heatin the room air, the damper I26 is moved to the position shown in broken lines in Fig. 13 so as to place the duct I I6 in communication with the room through the duct I04. This simultaneously places the upper end of the evaporator compartment in communication with the outside atmosphere through the duct I06.

To heat and recirculate room air exclusively, the damper I23 is adjusted to the position shown in broken lines, it being understood that for heating a mixture of outside air and room air with or without simultaneously exhausting room air, the damper I26 is retained in the broken line position and the damper I34 is adjusted to intermediate positions (not shown) in which the proportion of room air and outside air admitted to the intake chamber IIG may be varied at will.

The dampers I28 and I34 may be moved and positioned by any well-known means. For example, the dampers may be biased to the solid line positions by springs I44, and pull chains I40 may be used for pulling the dampers to the desired positions. The chains I46 terminate in accessible knobs I40 and suitable means, such as a keyhole slot arrangement (not shown) may be used detachably to engage the chains so as to retain the dampers in their adjusted positions against the bias of the springs.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is:

1. An air conditioning apparatus including a casing, an air cooling element in said casing. an air heating element in said casing, said casing havin an air intake chamber arranged for receiving room air and outside" atmosphere air to be conditioned by said cooling and heating elements and an outlet chamber arranged for receiving air conditioned by said elements and for discharging air to the room and to the outside atmosphere, means for propelling air from said intake chamber into contact with said cooling element and to said outlet chamber, means for propelling air into contact with said heating element and to said outlet chamber, a first damper means controlling the discharge of air from said outlet chamber, said damper means being movable to one position in which it directs the air cooled by said cooling element to the room and the air heated by said heating element to the outside atmosphere, and to another position in which it directs the air cooled by said cooling element to the outside atmosphere and the air heated by said heating element to the room, and a second damper means for controlling admission of room air and outside atmosphere air into said intake chamber, said second damper means being movable to one extreme position in which room air exclusively is directed to said cooling element and outside air exclusively is directed to said heating element and to another extreme position in which outside air exclusively is directed to said cooling element and room air exclusively is directed to said heating element, and also being movable, while the first damper means is in one of its two mentioned positions. to a plurality of intermediate positions for directing variable mixtures of room air and outside atmosphere air to said cooling element and to said heating element.

2. An air conditioning apparatus including a casing, means dividing said casing into an evaporator compartment and a condenser compartment, an evaporator in said evaporator compartment, a condenser in said condenser compartment, said casing having a single intake chamber communicating with said evaporator and condenser compartments and arranged for receiving room air and outside atmosphere air to be conditioned by said evaporator and said condenser, and having a single outlet chamber communicating with said compartments for receiving the air conditioned by said evaporator and said condenser and arranged to discharge the conditioned air to the room and to the outside atmosphere, means for propelling air from said intake chamber into said evaporator compartment and to said outlet chamber, means for propelling air from said intake chamber to said condenser compartment and into said outlet chamber, a first damper means controlling the discharge of air from said outlet chamber, said damper means bein movable to one position in which it directs air conditioned by said evaporator to the room and air conditioned by said condenser to the outside atmosphere, and to another position in which it directs the air conditioned by said evaporator to the outside atmosphere and the air conditioned by said condenser to the room, and a second damper means for controlling the admission of room air and outside air from said intake chamber into the evaporator and condenser compartments, said second damper means being movable to one extreme position in which room air exclusively is directed to said evaporator compartment and outside air exclusively is directed to the condenser compartment and to another extreme position in which outside air exclusively is directed to the evaporator compartment and room air exclusively is directed to the condenser compartment, and also being movable, while the first damper means is in one of its two mentioned positions, to a plurality of intermediate positions for directing variable mixtures of room air and outside air to said evaporator and condenser compartments.

3. An air conditioning apparatus as set forth in claim 1 and further including operating means for moving said first damper means from one to the other of its two mentioned positions, means yieldably connecting said operating means to said second damper means for moving the latter as far as it is free to move, and adjustable stop means for limiting the movement of said second damper means toward its extreme positions, whereby the second damper means is positioned to provide desired mixtures of room air and outside atmosphere air to said coolin element and to said heating element when the operating means moves the first damper means to its said one position and to provide different desired mixtures when the operating means moves the first damper means to its said other position.

4. The structure recited in claim 1 in which said intake and outlet chambers are disposed near the bottom and top of said casing, respectively, together with a rotatable shaft, means rigidly mounting said first damper means on the upper portion of said shaft so as to be rotatable therewith from one of its positions to the other, means yieldably connecting said second damper means to the lower portion of said shaft so as to be rotatable therewith in the absence of means limiting the movement of said second damper means, and adjustable limiting means adapted to be positioned in the path of movement of said second damper means for limiting the movement thereof and thus determining the plurality of intermediate positions to which said second damper means is to be set for regulating the mixture of room and outside air admitted to said intake chamber.

5. The structure recited in claim 1 in which said intake and outlet chambers are disposed side by side near the top of the casing. together with means for movably supporting each of said damper means, and means for moving said first and second damper means and for retaining them in various positions independently of each other.

CLIFFORD S. CODY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,216,427 Arnold Oct. 1, 1940 2,309,224 Terry Jan. 26, 1943 2,401,560 Graham June 4, 1946 

